Young , low-mass stars in the solar neighborhood are vital for completing the mass function for nearby , young coeval groups , establishing a more complete census for evolutionary studies , and providing targets for direct-imaging exoplanet and/or disk studies .
We present properties derived from high-resolution optical spectra for 336 candidate young nearby , low-mass stars .
These include measurements of radial velocities and age diagnostics such as H \alpha and Li \lambda 6707 equivalent widths .
Combining our radial velocities with astrometry from Gaia DR2 , we provide full 3D kinematics for the entire sample .
We combine the measured spectroscopic youth information with additional age diagnostics ( e.g. , X-ray and UV fluxes , CMD positions ) and kinematics to evaluate potential membership in nearby , young moving groups and associations .
We identify 78 objects in our sample as bonafide members of 10 different moving groups , 15 of which are completely new members or have had their group membership reassigned .
We also reject 44 previously proposed candidate moving group members .
Furthermore , we have newly identified or confirmed the youth of numerous additional stars that do not belong to any currently known group , and find 69 co-moving systems using Gaia DR2 astrometry .
We also find evidence that the Carina association is younger than previously thought , with an age similar to the \beta Pictoris moving group ( \sim 22 Myr ) .